Refactor props to all be in props module, remove most custom ULEs (#5555)

Some progress on #5127. Now
there are only two `make_ule`s in zerovec, for enums.

Followups from #5548

Author: Manishearth

components/properties/src/props.rs

@@ -17,7 +17,6 @@
 
 pub mod bidi;
 pub mod names;
-pub mod props;
 
 pub use names::{
     BidiClassNameToValueV1Marker, BidiClassValueToLongNameV1Marker,
@@ -41,6 +40,7 @@ pub use names::{
     WordBreakValueToShortNameV1Marker,
 };
 
+pub use crate::props::gc::GeneralCategoryULE;
 pub use bidi::BidiAuxiliaryPropertiesV1Marker;
 
 use crate::script::ScriptWithExt;

components/properties/src/provider.rs

@@ -6,7 +6,6 @@
 //! values in an efficient structure.
 
 use crate::props::Script;
-use crate::provider::props::ScriptULE;
 use crate::provider::*;
 
 use core::iter::FromIterator;
@@ -51,7 +50,7 @@ impl ScriptWithExt {
 }
 
 impl AsULE for ScriptWithExt {
-    type ULE = ScriptULE;
+    type ULE = <u16 as AsULE>::ULE;
 
     #[inline]
     fn to_unaligned(self) -> Self::ULE {